Delta Electronics Programmable Logic Controller DVP-PLC - Manual (Page 166)

3 Basic Instructions
DVP-PLC Application Manual 3-12
Mnemonic Function Program steps
LDF Falling-edge detection operation 1
Controllers
ES EX SS SA SX SC EH SV
X0 ~ X377 Y0 ~ Y377 M0 ~ M4095 S0 ~ S1023 T0 ~ T255 C0 ~ C255 D0 ~ D9999
Operand
9 9 9 9 9 9 -
Explanations:
The method of using LDF is the same as using LD, but the actions of the two instructions differ. LDF saves the current
content and store the detected status of falling-edge to the accumulative register.
Program Example:
Ladder diagram: Instruction code: Operation:
LDF X0 Starting X0 falling-edge detection
AND X1 Series connecting A contact of X1
X0 X1
Y1
OUT Y1 Driving Y1 coil
Mnemonic Function Program steps
ANDP Rising-edge series connection 1
Controllers
ES EX SS SA SX SC EH SV
X0 ~ X377 Y0 ~ Y377 M0 ~ M4095 S0 ~ S1023 T0 ~ T255 C0 ~ C255 D0 ~ D9999
Operand
9 9 9 9 9 9 -
Explanations:
ANDP instruction is used in the series connection of the contacts’ rising-edge detection.
Program Example:
Ladder diagram: Instruction code: Operation:
LD X0 Loading in A contact of X0
ANDP X1 X1 rising-edge detection in series connection
X1 X0
Y1
OUT Y1 Driving Y1 coil
Mnemonic Function Program steps
ANDF Falling-edge series connection 1
Controllers
ES EX SS SA SX SC EH SV
X0 ~ X377 Y0 ~ Y377 M0 ~ M4095 S0 ~ S1023 T0 ~ T255 C0 ~ C255 D0 ~ D9999
Operand
9 9 9 9 9 9 -
Explanations:
ANDF instruction is used in the series connection of the contacts’ falling-edge detection.
[Program Example:
Ladder diagram: Instruction code: Operation:
LD X0 Loading in A contact of X0
ANDF X1 X1 falling-edge detection in series connection
X1 X0
Y1
OUT Y1 Drive Y1 coil